Add support for all blendmodes if we have GL_KHR_blend_equation_advanced.

gpu/command_buffer/client/gles2_interface_stub_impl_autogen.h

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // This file is auto-generated from
 // gpu/command_buffer/build_gles2_cmd_buffer.py
 // It's formatted by clang-format using chromium coding style:
 //    clang-format -i -style=chromium filename
 // DO NOT EDIT!
 
@@ skipping 833 matching lines @@
     GLfloat /* uv_x */,
     GLfloat /* uv_y */,
     GLfloat /* uv_width */,
     GLfloat /* uv_height */) {
 }
 void GLES2InterfaceStub::MatrixLoadfCHROMIUM(GLenum /* matrixMode */,
                                              const GLfloat* /* m */) {
 }
 void GLES2InterfaceStub::MatrixLoadIdentityCHROMIUM(GLenum /* matrixMode */) {
 }
+void GLES2InterfaceStub::BlendBarrierKHR() {
+}
 #endif  // GPU_COMMAND_BUFFER_CLIENT_GLES2_INTERFACE_STUB_IMPL_AUTOGEN_H_